The Royal United Services Institute report names the most notable vulnerability as 'increased peer and near-peer threat from Chinese and Russian long-range precision missiles'.

It adds: 'China and Russia appear to have focused many of their efforts on being able to put at risk the key Western assets that are large, few in number and expensive … The advancing capabilities of potential adversaries of the UK should be a genuine concern.'

The authors add: 'The advancing capabilities of potential adversaries of the UK should be a genuine concern.'

Co-author Professor Trevor Taylor, a professorial fellow at RUSI, said: 'UK defence policy prioritises the capability to project force to areas of concern and to deter attacks on British assets and allies.

'It has become much cheaper to destroy major systems and platforms than to develop and build them, making large-scale attacks on a single target more likely', the report said

'The advancing capabilities of potential adversaries in Northern Europe, the Middle East and even East Asia need to be taken into account in reviews of UK defence policy and military tasks, British and Nato approaches to deterrence strategy, and the priorities for UK capability development.'

Last month Britain's biggest ever warship, HMS Queen Elizabeth, squeezed out of the Rosyth basin in Scotland and set sail on her maiden voyage.

Once it is handed over to the Royal Navy it will boast 24 of the world's most advanced stealth fighter jets. The F-35B Lightning II and its radar can track objects the size of snooker balls 20km away.

It will also have a modern-day Gatling gun known as Phalanx, which fires 20mm shells at a rate of 3,000 rounds a minute.

An MOD spokesperson said: 'We keep all threats under constant review and we are confident our new aircraft carrier, and other state-of-the-art equipment, is well protected thanks to defensive systems we have invested in as part of our £178 billion equipment plan.'